Powdery mildew is a vulgar disease on many types of industrial plant . In fact , it is one of the oldest plant diseases on record – Theophrastis wrote of powdery mildew on blush wine in 300 B.C. Although dissimilar species of fungi make the disease on different plant ( Erysipheinfects vegetable crop and flowers;Podosphaeraspecies infects apples and stone fruits;Sphaerothecaspecies infects Berry , roses , some vegetable crops , and stone fruits ; andUncinula necatorinfects grapes ) , the infections are all characterized by a powdery white to gray fungous growth on leaves , stems and heads .
adverse to pop belief , powdery mildew generally does not command complimentary water to establish and uprise . contagion can actually occur on dry leaves . Warm temperatures and louche conditions encourage the fungus to grow and open . However , the spore and mycelium are sensitive to utmost heat and direct sunlight .
Symptoms
Powdery mildew ordinarily show up on leaf and stem surfaces and does not direct affect most vegetable fruit . However , it can pretend the flavor of melons and mash and reduce their output . Woody metal money such as grapes , fruit tree , roses , crape myrtle , and sycamore are more severely affected ; new growth is often distorted . The young yield of apples and grapes can also modernize rough peel due to powdery mildew .
Life Cycle
All species of powdery mildew fungus require living industrial plant tissue to grow . On perennials , they survive on buds and stem turn tissue paper . sure sens will also act as master of ceremonies through the wintertime . The optimal temperature for infection is between 68 to 77 degrees F and relative humidness between 40 to 100 % is sufficient for the spore to germinate . Low , diffuse sparkle also seems to favor powdery mildew developing .
The mildew can diffuse rapidly since the disease cycle can be completed in as piddling as 72 hours . However , it commonly takes 7 - 10 days from the meter of contagion to the development of symptoms and secondary spore yield .
Management
In most case , good cultural practices will adequately control powdery mildew :
Organic Sprays
Sulfur is highly effective against powdery mould if used in a protectant program with a lower limit of 7 to 14 day between applications . Garlic naturally contains high levels of sulfur and a few cloves crushed in water system can be used to make a homemade spray . put on a sulfur - based fungicideat first evidence of mildewand repetition coating as necessary . Proper timing of fungicide diligence is critical to successful control so ensure to start out at the first sign of the disease .
However , sulfur can be damaging to some squash and melon varieties . Another pick is to spray once a week with a solution of baking soda . bake tonic increases the Earth’s surface pH of the leaf making it unsuitable for the growth of powdery mold spores . Be sure to spray the undersurface of leafage as well as the upper surfaces when using any of these spray .
Here ’s a recipe to make your own spray :
Before treating your plants , test the nebulizer on a few leaves to check that they are nottoo sensitive .
For more info on powdery mildew , you may refer to the following website :
Arzeena Hamiris an agronomist and President of Terra Viva Organics . When she ’s not planting peas or picking courgette , she answer questions about constitutive horticulture at : advice@tvorganics.com
